qtile-examples VS .nixpkgs

I have also combined this with some navigation over different focus/screens that I found here: https://github.com/qtile/qtile-examples/blob/master/traverse.py

Did you look at the linked examples in the official repo? I'm not aware of any other resource like that, except for some bits I found through this subreddit.

There is a qtile-examples repository, full of people's setups and tweaks.

basic notification system and example server

Most importantly, there are lines that define keybindings to start programs. I don't use qtile, but I think this example will help you figure things out. For instance, there is the # start specific apps section that explains that (with the given config) you have to press the mod key + n to start the browser or mod key + Enter to start the terminal.

Declaration for each 'theme'. (See qtile-examples for how to separate qtile into multiple files.)

I'm not completely dumbstruck, for example I can see that in this config the dev uses functions and hooks (idk what hooks are, sounds like a way to add event-driven functionality) to automatically set the window type to floating if the window name is equal to x.

You can find some example configs at qtile-examples but, note, some of those configs are quite old.

https://github.com/qtile/qtile-examples/blob/92c2659e771b42ca52342996181f2c1b3fdb0324/cjbarnes/config.py (line 60)

I end up with my own thing based on a local "collection package" named all. You can look into my setup at https://github.com/kamilchm/.nixpkgs. It's not a generic solution but you can clone my config and try to customize it.